[croatianboii]

My exam for chemistry is tomorrow and I need help with a few questions.

1) Use NaF as the example to explain how water dissolves solutes.

2) The density of a gas is 5g/L at 79 degrees celcius and and 100kPa. Calculate the molar mass of the gas.

3) A 7mL sample of acetic acid was titrated using 3mL of 4M NaOH. Use the equation CH3COOH(aq)+NaOH(aq) yields CH3COONa(aq)+H20(l) to answer the following.
a) calculate the number of moles of base used in the titration.
b)calculate the moles of acid present in the sample.
c)calculate the concentration of the acid.

[Astrokel]

You need to show some attempt!